A Census of Starburst Regions in Luminous Infrared Galaxies as Unveiled by the Jansky VLA

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

Galaxy collisions are among the most energetic events in the local Universe. They are ideal labs for studying strong bursts of star formation and the feeding of giant central black holes. They also represent a preview to the future of the Milky Way Galaxy, which will collide with the Andromeda Galaxy in 5 billion years. The collision process produces debris that hide much of the activity from optical telescopes. In this study, a subset of the most extreme nearby colliding galaxies are observed with the upgraded Very Large Array to create detailed radio maps of their hidden star-forming regions. The measured properties of these regions will be compared with those in normal galaxies. This will allow a determination of the physical conditions that make star formation in galaxy collisions so extreme. Concurrent with the above study, the PI will lead the Charlottesville part of the successful National Astronomy Consortium (NAC). The NAC is an undergraduate program designed to increase the number of underrepresented groups in STEM fields. Participating students work on research projects and receive long-term career mentoring. Low-redshift luminous infrared galaxies (LIRGs) are the sites of gas-rich galaxy interactions and mergers, and are prime systems for studying the environments of extreme starbursts and nascent active galactic nuclei (AGN). Both phenomena occur in compact, dust-enshrouded regions that are responsible for up to 99% of the bolometric luminosity of LIRGs. The present proposal makes use of high- resolution, 2-37 GHz observations with the upgraded Jansky VLA (JVLA) of a complete sample of IRAS RBGS LIRGs in the equatorial range declination = +20 to -20 degrees. These data will be used to isolate their compact, energetic regions and to characterize their physical properties relative to star-forming regions in nearby normal star-forming galaxies. The declination range of the sample ensures the legacy value of the dataset. Data products will primarily be disseminated through the NASA Extragalactic Database. The National Astronomy Consortium (NAC) is a program designed to increase the number of students from underrepresented and underserved groups and those otherwise overlooked by the traditional academic pipeline into STEM or STEM-related careers. In addition to research opportunities, the NAC provides career development and year-round mentorship of its participants. The PI will take on the role as NAC Project Scientist and run the Charlottesville NAC site. NAC students working under the research supervision of the PI will work on JVLA observations of LIRGs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.